Celtic fans heading into pre-season have grown accustomed to the annual anxiety of the transfer window — the creeping fear that the club's best will be prised away before a ball has been kicked in anger. This summer, that anxiety has arrived earlier than most, and with rather more credibility attached to it.

Martin O'Neill, in his second stint at Parkhead, has reportedly resigned himself to selling both Arne Engels and Daizen Maeda, while also planning conversations with club captain Callum McGregor about his future following reports that McGregor has signed with a new agency. With Colombian striker Camilo Duran — signed from Azerbaijani side Qarabag — still the only confirmed arrival of the summer, it is a window that has, so far, raised more questions than it has answered.

Engels: Goals, assists and big-moment contributions

When Engels arrived from Augsburg in the summer of 2024, the comparison to Matt O'Riley was always going to be unavoidable. O'Riley had scored 19 goals in 49 appearances in his final season before Brighton came calling, and the Belgian was, broadly speaking, brought in to fill that creative void. He has not yet matched those numbers outright, but the trajectory is encouraging.

Ten goals in his first full season and seven last term might read as modest on paper, but the context matters. Both of his most recent goals came in trophy-clinching moments — the final-day Scottish Premiership showdown against Hearts, and then the Scottish Cup final against Dunfermline Athletic. Eight assists last season alone further underlines his importance to how Celtic build and score. He is only 22, capped four times for Belgium, and contracted until 2028. Nottingham Forest were reportedly interested last term, and while a move did not materialise, it seems unlikely the English market has gone cold on him.

Maeda: A peak season and World Cup experience

Daizen Maeda hit his personal ceiling in 2024-25 — 33 goals in 51 appearances is the kind of return that tends to attract serious attention. He has not quite touched those heights since, but 17 goals in the 2025-26 campaign and 38 career assists across his time at Celtic still paint the picture of a player who has been indispensable to five league title wins.

Ange Postecoglu, speaking during this summer's finals, described Maeda's pressing and closing-down abilities as genuinely world-class, and that off-ball work is precisely what makes him attractive to clubs operating at the top of the European game. He still only turns 29 this year, carries World Cup experience with Japan, and crucially has just one year remaining on his contract. Celtic have two windows, at most, to bank a proper fee — after that, the leverage evaporates.

McGregor: Twelve years of heartbeat

If there is a player whose departure would feel genuinely seismic at Celtic Park, it is Callum McGregor. Since breaking into the first team in 2014, the former Scotland midfielder has made 576 appearances for the club, scoring 77 goals and contributing 84 assists. He has 26 honours to his name, including 11 league titles, and has been captain since succeeding Scott Brown in 2021.

At 33, the conversations around his future are different in nature to those around Engels or Maeda. This is not about Celtic cashing in on peak-value asset — it is about whether McGregor himself still feels the club matches his own ambition. In April, he was candid about it, saying he was happy to finish at Celtic only if the club continued to push for success. The late-season title rescue under O'Neill will have helped, but his comments linger. He is contracted until 2028, and while one significant move may still be in him, it feels more likely to be his decision than the club's.

A window that needs answers

Celtic open their Premiership title defence at home to Dundee on 3 August, with a trip to Kilmarnock to follow. O'Neill will want clarity — and ideally some signings — before that first whistle. The market knows Celtic's players are good. The concern, for supporters filling the Jock Stein Stand each fortnight, is whether the club's replacements will be good enough.

Frequently asked

When does Celtic's 2026-27 Scottish Premiership season start?
Celtic begin their title defence at home to Dundee on 3 August, with a trip to Kilmarnock following shortly after.
How long is Daizen Maeda's contract at Celtic?
Maeda has just one year remaining on his current Celtic contract, meaning the club have a limited window to sell him for a significant fee before he could leave for nothing.
Has Callum McGregor said he wants to leave Celtic?
McGregor has not asked for a transfer, but he did say in April that he would only be happy to finish his career at Celtic if the club continued to push for success. Reports of him signing with a new agency have fuelled speculation about his future.